Electronic Article Surveillance (“EAS”) systems are often used by retail stores in order to minimize loss due to theft. One common way to minimize retail theft is to attach a security tag to an article such that an unauthorized removal of the article can be detected. In some scenarios, a visual or audible alarm is generated based on such detection. For example, a security tag with an EAS element (e.g., an acousto-magnetic element) can be attached to an article offered for sale by a retail store. An EAS interrogation signal is transmitted at the entrance and/or exit of the retail store. The EAS interrogation signal causes the EAS element of the security tag to produce a detectable response if an attempt is made to remove the article without first detaching the security tag therefrom. The security tag must be detached from the article upon purchase thereof in order to prevent the visual or audible alarm from being generated.
One type of EAS security tag can include a tag body which engages a tack. The tack usually includes a tack head and a sharpened pin extending from the tack head. In use, the pin is inserted through the article to be protected. The shank or lower part of the pin is then locked within a cooperating aperture formed through the housing of the tag body. In some scenarios, the tag body may contain a Radio Frequency Identification (“RFID”) element or label. The RFID element can be interrogated by an RFID reader to obtain RFID data therefrom.
The EAS security tag may be removed or detached from the article using a detaching unit. Examples of such detaching units are disclosed in U.S. Pat. No. 5,426,419 (“the '419 patent), U.S. Pat. No. 5,528,914 (“the '914 patent”), U.S. Pat. No. 5,535,606 (“the '606 patent”), U.S. Pat. No. 5,942,978 (“the '978 patent”) and U.S. Pat. No. 5,955,951 (“the '951 patent”). The detaching units disclosed in the listed patents are designed to operate upon a two-part hard EAS security tag. Such an EAS security tag comprises a pin and a molded plastic enclosure housing EAS marker elements. During operation, the pin is inserted through an article to be protected (e.g., a piece of clothing) and into an aperture formed through at least one sidewall of the molded plastic enclosure. The pin is securely coupled to the molded plastic enclosure via a clamp disposed therein. The pin is released by a detaching unit via a probe. The probe is normally retracted within the detaching unit. Upon actuation, the probe is caused to travel out of the detaching unit and into the enclosure of the EAS security tag so as to release the pin from the clamp or disengage the clamp from the pin. Once the pin is released from the clamp, the EAS security tag can be removed from the article.
While EAS security tags help reduce retail theft, improper use of the detaching unit is an ever growing problem that is inhibiting the effectiveness of the security tags. For example, an unscrupulous store employee may conspire to allow customers to steal merchandise by a practice known as “sweethearting ”.“Sweethearting ” involves collusion between the store employee and a customer. Typically, a cashier scans an inexpensive item for the customer to ring a sale and apparently complete the transaction. But then the cashier uses a detaching unit to remove the EAS security tag from a much more expensive item which was not scanned. The customer is then free to leave the premises with the expensive item without having paid therefore. In effect, “sweethearting ” can cost businesses a relatively large amount of dollars each year.
There are various methods which attempt to prevent “sweethearting ”. For example, a first method involves using a smart detaching unit. The smart detaching unit is communicatively coupled to a Point Of Sale (“POS”) terminal and configured to read RFID data from the RFID element of the EAS security tag. In this case, a detachment process is completed only if purchase of the item can be verified through the POS data (e.g., by determining if an identifier read from the RFID element matches an identifier stored in a database). The verification is facilitated by a controlled Radio Frequency (“RF”) field produced around the smart detaching unit. The RFID data can only be read when the EAS security tag is placed into the smart detaching unit. This approach is efficient and practical for mechanical detaching of the security tag from the item. However, the smart detaching unit does not allow the required amount of control for the antenna of the RFID reader thereof. Therefore, the RFID data of an EAS security tag, which is merely in proximity to the smart detaching unit rather than actually in the smart detacher unit, may be erroneously read by the RFID reader of the smart detaching unit.
A second method which attempts to prevent “sweethearting ” requires a store employee to manually verify that the item having the EAS security tag detached therefrom is really being purchased. As should be understood, such manual verification may be unreliable if the store employee is unscrupulous.
A third method which attempts to prevent “sweethearting ” does not involve verifying that the pin has been removed from the EAS security tag, i.e., actually detached from the article being purchased. Instead, the third method involves determining that the EAS security tag is in a certain area of the retail store.